CLI stopped working error

I get "CLI stopped working" error when i press the upload button.I used the sample code from one of the website to upload file into the database column. I use Laravel 5.2.39. command used: php artisan serve

Code:(Only test version)

Form.blade.php

<form method="post" enctype="multipart/form-data"  action="/upload_file">

<input type="file" name="file" />
<input type="submit" name="submit" value="upload" />
</form>  

Routes.php(Not an ideal place to code this but it is only for file upload test purpose) Route::get('/upload_form', function() { $data['files'] = Attachment::get(); return View::make('form', $data); });

Route::post('/upload_file', function()
{
$rules = array(
    'file' => 'required|mimes:doc,docx,pdf',
    );

$validator = Validator::make(Input::all(), $rules);

if(Input::hasFile('file'))
{
   $f = Input::file('file');
   $att = new Attachment;
   $att->name = $f->getClientOriginalName();
   $att->file = base64_encode(file_get_contents($f->getRealPath()));
   $att->mime = $f->getMimeType();
   $att->size = $f->getSize();

   $att->save();

   return Redirect::to('/upload_form');
}

});

Has anyone encountered this issue? Need help.

via Chebli Mohamed